Different methods for production of flat panels are known, particularly for production of false ceilings in the construction field.
A first solution consists of using widths of PVC, fused and factory pre-assembled in order to form a sheet. This sheet is then secured along its edges to a frame formed, for example, by means of profiled fastening sections. In order to obtain a suitably taut panel, placement of the sheet must be entrusted to an expert, and requires specific equipment.
A second solution, easier to implement, consists of using sheets produced from non-woven materials. These materials can be painted and can have decorative patterns. Easy to install, they make possible frequent changes in decor, but they need to be taut in order to avoid any folding or buckling phenomena. This tightening is generally difficult, and does not enable one to obtain homogeneous tension in all directions of the sheet.
A third solution, particularly described in the publication FR-A-2 552 473, consists of using a heat-stretchable sheet. Before attachment to the frame, the sheet is subjected to a large temperature increase in order to stretch it. In its stretched state, it is attached along its edges in a frame formed by retaining profiled sections. The source of heat is then eliminated so that the sheet contracts by cooling and tightens on the frame. Before it is placed, this sheet must be cut precisely to dimensions that are compatible with those of the frame, anticipating its percentage of stretching and contraction. Cutting to dimensions which are too small will not allow this sheet to be stretched enough to secure it to the frame. Cutting to dimensions which are too large will generate waste and therefore extra material cost. Moreover, in order to enable stretching the sheet, and to obtain, after attachment, a homogeneous tension over its whole surface, the sheet must be heated entirely in one pass to a temperature of approximately 50–60° C. In order to obtain this homogeneous temperature rise, the whole room in which the sheet is going to be placed must be heated to this temperature. Consequently, this method is difficult to use in large rooms and by non-specialized persons. It generates high costs of implementation, as well as difficult work conditions for the placement personnel. Moreover, this heating can cause deterioration of other elements present in the room (furniture, floor covering, . . . ).
A fourth solution, particularly described in the publication FR-A-2 619 531, consists of using a heat-shrinkable cloth secured on the frame; the cloth is attached, not tightly, to the frame and is then subjected to a large temperature increase allowing it to contract and tighten on the frame. This cloth is, for example, produced from PVC. This method thus makes it possible to produce a panel simply, and without requiring the involvement of experts. Nevertheless, this method does not allow one to obtain an optimal result, since the panel is not homogeneously taut in all directions.
Therefore, there is no solution providing a satisfactory response to the problem that is posed.